diff --git a/.github/workflows/codeql.yml b/.github/workflows/codeql.yml
index e8af47e..57f2542 100644
--- a/.github/workflows/codeql.yml
+++ b/.github/workflows/codeql.yml
@@ -15,8 +15,8 @@ jobs:
   analyze:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v6
-      - uses: github/codeql-action/init@v4
+      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+      - uses: github/codeql-action/init@5595ccaf912efad79be6eef63a5619ff05969be3 # v4
         with:
           languages: javascript-typescript
-      - uses: github/codeql-action/analyze@v4
+      - uses: github/codeql-action/analyze@5595ccaf912efad79be6eef63a5619ff05969be3 # v4
diff --git a/.github/workflows/dependency-review.yml b/.github/workflows/dependency-review.yml
index 91d2d46..46cb662 100644
--- a/.github/workflows/dependency-review.yml
+++ b/.github/workflows/dependency-review.yml
@@ -10,5 +10,5 @@ jobs:
   review:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v6
-      - uses: actions/dependency-review-action@v4
+      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+      - uses: actions/dependency-review-action@a1d282b36b6f3519aa1f3fc636f609c47dddb294 # v5.0.0
diff --git a/.github/workflows/publish.yml b/.github/workflows/publish.yml
index cd35b83..ac32afa 100644
--- a/.github/workflows/publish.yml
+++ b/.github/workflows/publish.yml
@@ -14,8 +14,8 @@ jobs:
     runs-on: ubuntu-latest
     environment: npm
     steps:
-      - uses: actions/checkout@v6
-      - uses: actions/setup-node@v6
+      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+      - uses: actions/setup-node@820762786026740c76f36085b0efc47a31fe5020 # v7.0.0
         with:
           node-version: 24
           registry-url: https://registry.npmjs.org
diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index aec8c83..7e7cfc7 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -16,8 +16,8 @@ jobs:
         node-version: [20, 22, 24]
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v6
-      - uses: actions/setup-node@v6
+      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+      - uses: actions/setup-node@820762786026740c76f36085b0efc47a31fe5020 # v7.0.0
         with:
           node-version: ${{ matrix.node-version }}
           package-manager-cache: false
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 2011f8f..ae57ce8 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,13 @@
 
 All notable changes will be documented here. The project follows Semantic Versioning after `1.0.0`; pre-1.0 releases may refine APIs while preserving documented security behavior where possible.
 
+## 0.1.1 - 2026-08-09
+
+- Removed all legacy MD5 and MD5-hash paths from the Vonage adapter.
+- Pinned GitHub Actions to immutable commits and updated their major releases.
+- Added Cloudflare Pages security headers, including a strict Content Security Policy.
+- Updated release status, website metadata, and security regression coverage.
+
 ## 0.1.0 - 2026-08-09
 
 - Added Twilio, Telnyx, Vonage, Plivo V3, and Generic HMAC validators.
diff --git a/README.md b/README.md
index 3b8de2f..17cf2d9 100644
--- a/README.md
+++ b/README.md
@@ -6,7 +6,7 @@
 
 Security-first webhook validation for applications that receive SMS events from Twilio, Telnyx, Vonage, Plivo, or a custom HMAC provider. The package combines signature verification, timestamp checks, replay protection, payload validation, PII redaction, Express middleware, and a defensive localhost tester.
 
-> Status: `0.1.0` release candidate. Validate the exact provider configuration and test in staging before production use.
+> Current release: `0.1.1`. The API is pre-1.0; validate the exact provider configuration and test in staging before production use.
 
 ## Why
 
@@ -96,7 +96,7 @@ Use `timestamp` and `timestampSeparator` when your signing contract includes a t
 | Plivo V3 | HMAC-SHA256 over URL, sorted parameters, and nonce | Unique nonce plus message UUID |
 | Generic HMAC | SHA-256 by default; configurable encoding/prefix | Configurable timestamp and event ID |
 
-Vonage's legacy MD5 modes are rejected by default. If migration compatibility is unavoidable, pass `allowLegacyMd5: true` explicitly and document the risk.
+Vonage's legacy MD5 modes are not supported. Configure HMAC-SHA256 or stronger in the provider dashboard.
 
 ## Payload validation and logging
 
@@ -147,7 +147,7 @@ See [CLI safety and interpretation](docs/cli.md).
 - Constant-time comparison for shared-secret signatures.
 - Raw-body and exact-URL validation where required.
 - Atomic replay-store interface.
-- CodeQL, dependency review, Dependabot, tests, and release provenance workflow.
+- CodeQL, dependency review, Dependabot, tests, and trusted npm publishing with provenance.
 - Responsible disclosure process in [SECURITY.md](SECURITY.md).
 
 This project reduces common implementation mistakes; it is not a security certification. Review provider documentation, proxy URL handling, key rotation, storage availability, and application side effects for your environment.
diff --git a/docs/providers.md b/docs/providers.md
index 374b057..015aa7b 100644
--- a/docs/providers.md
+++ b/docs/providers.md
@@ -23,7 +23,7 @@ Official reference: <https://developers.telnyx.com/docs/messaging/messages/recei
 
 ## Vonage SMS
 
-Signed inbound SMS webhooks must be enabled for the account. Vonage supports legacy MD5 and HMAC variants. Configure HMAC-SHA256 or stronger; this project rejects MD5 modes unless `allowLegacyMd5` is explicitly enabled.
+Signed inbound SMS webhooks must be enabled for the account. Configure HMAC-SHA256 or stronger. Legacy MD5 modes are intentionally unsupported.
 
 Official reference: <https://developer.vonage.com/en/getting-started/concepts/signing-messages>
 
diff --git a/package-lock.json b/package-lock.json
index d0a6c57..f7ba12d 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1,12 +1,12 @@
 {
   "name": "secure-sms-webhook",
-  "version": "0.1.0",
+  "version": "0.1.1",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "secure-sms-webhook",
-      "version": "0.1.0",
+      "version": "0.1.1",
       "license": "MIT",
       "bin": {
         "secure-sms-webhook": "cli/tester.js"
diff --git a/package.json b/package.json
index 0d953d2..0894326 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "secure-sms-webhook",
-  "version": "0.1.0",
+  "version": "0.1.1",
   "description": "Security-first SMS webhook signature validation, replay protection, payload checks, PII redaction, and a defensive local tester.",
   "type": "module",
   "main": "./src/index.js",
@@ -56,7 +56,7 @@
     "type": "git",
     "url": "git+https://github.com/receive-sms-live/secure-sms-webhook.git"
   },
-  "homepage": "https://github.com/receive-sms-live/secure-sms-webhook#readme",
+  "homepage": "https://secure-sms-webhook.pages.dev/",
   "bugs": {
     "url": "https://github.com/receive-sms-live/secure-sms-webhook/issues"
   },
diff --git a/site/_headers b/site/_headers
new file mode 100644
index 0000000..bd6589e
--- /dev/null
+++ b/site/_headers
@@ -0,0 +1,10 @@
+/*
+  Content-Security-Policy: default-src 'self'; base-uri 'none'; connect-src 'none'; font-src 'self'; form-action 'none'; frame-ancestors 'none'; img-src 'self' data:; object-src 'none'; script-src 'self' 'sha256-Kv6W6QJhArV5y6iipxf2v0T8NzCHSw8ojkc8GayXxFs='; style-src 'self'; upgrade-insecure-requests
+  Cross-Origin-Opener-Policy: same-origin
+  Cross-Origin-Resource-Policy: same-origin
+  Permissions-Policy: camera=(), geolocation=(), microphone=(), payment=(), usb=()
+  Referrer-Policy: strict-origin-when-cross-origin
+  Strict-Transport-Security: max-age=31536000; includeSubDomains
+  X-Content-Type-Options: nosniff
+  X-Frame-Options: DENY
+  X-XSS-Protection: 0
diff --git a/src/index.d.ts b/src/index.d.ts
index 209c00d..56a311b 100644
--- a/src/index.d.ts
+++ b/src/index.d.ts
@@ -61,8 +61,7 @@ export interface VonageOptions {
   params: Record<string, unknown>;
   signature?: string;
   secret: string;
-  algorithm?: 'md5hash' | 'md5' | 'sha1' | 'sha256' | 'sha512';
-  allowLegacyMd5?: boolean;
+  algorithm?: 'sha1' | 'sha256' | 'sha512';
   maxAgeSeconds?: number | false;
   maxFutureSkewSeconds?: number;
   now?: number;
diff --git a/src/providers/vonage.js b/src/providers/vonage.js
index 949d343..92418df 100644
--- a/src/providers/vonage.js
+++ b/src/providers/vonage.js
@@ -1,4 +1,3 @@
-import { createHash } from 'node:crypto';
 import {
   canonicalPairs,
   configurationFailure,
@@ -12,8 +11,6 @@ import {
 import { validateTimestamp } from '../policies/timestamp.js';
 
 const VONAGE_ALGORITHMS = new Map([
-  ['md5hash', 'md5hash'],
-  ['md5', 'md5'],
   ['sha1', 'sha1'],
   ['sha256', 'sha256'],
   ['sha512', 'sha512'],
@@ -36,9 +33,6 @@ export function createVonageSignature({ params, secret, algorithm = 'sha256' })
     throw new TypeError(`Unsupported Vonage algorithm: ${algorithm}`);
   }
   const data = canonicalVonageParams(params);
-  if (normalized === 'md5hash') {
-    return createHash('md5').update(`${data}${secret}`).digest('hex');
-  }
   return hmacBytes(normalized, secret, data).toString('hex');
 }
 
@@ -50,20 +44,12 @@ export function verifyVonageWebhook(options) {
       signature = params?.sig,
       secret,
       algorithm = 'sha256',
-      allowLegacyMd5 = false,
       maxAgeSeconds = 300,
       maxFutureSkewSeconds = 30,
       now,
     } = options || {};
     if (!signature) return invalid(provider, 'MISSING_SIGNATURE', 'Vonage sig parameter is missing.');
     const normalized = String(algorithm).toLowerCase().replace(/[^a-z0-9]/g, '');
-    if (!allowLegacyMd5 && (normalized === 'md5' || normalized === 'md5hash')) {
-      return invalid(
-        provider,
-        'INSECURE_ALGORITHM',
-        'Legacy MD5 validation is disabled. Configure Vonage HMAC-SHA256 or opt in explicitly.',
-      );
-    }
     if (params?.timestamp === undefined) {
       return invalid(provider, 'MISSING_TIMESTAMP', 'Vonage timestamp parameter is missing.');
     }
diff --git a/tests/integration.test.js b/tests/integration.test.js
index c479e6b..ba23c0d 100644
--- a/tests/integration.test.js
+++ b/tests/integration.test.js
@@ -1,4 +1,5 @@
 import assert from 'node:assert/strict';
+import { createHash } from 'node:crypto';
 import { readFileSync } from 'node:fs';
 import { spawnSync } from 'node:child_process';
 import test from 'node:test';
@@ -68,11 +69,19 @@ test('CLI help exits successfully', () => {
 
 test('documentation site is static, disclosed, and contains no secret form fields', () => {
   const html = readFileSync('site/index.html', 'utf8');
+  const headers = readFileSync('site/_headers', 'utf8');
+  const structuredData = html.match(/<script type="application\/ld\+json">([\s\S]*?)<\/script>/)?.[1];
+  const structuredDataHash = createHash('sha256').update(structuredData).digest('base64');
   assert.match(html, /Secure SMS Webhook Validator/);
   assert.match(html, /receive-smss\.live\/sms\/us/);
   assert.match(html, /maintained by the same team/i);
   assert.doesNotMatch(html, /type=["']password/);
   assert.doesNotMatch(html, /<input[^>]+name=["'][^"']*(secret|token|key)/i);
+  assert.match(headers, /Content-Security-Policy:/);
+  assert.match(headers, /frame-ancestors 'none'/);
+  assert.match(headers, /X-Frame-Options: DENY/);
+  assert.ok(headers.includes(`'sha256-${structuredDataHash}'`));
+  assert.doesNotMatch(headers, /unsafe-inline|unsafe-eval/);
 });
 
 test('package surface does not contain placeholder runtime imports', () => {
diff --git a/tests/providers.test.js b/tests/providers.test.js
index f02122b..27d6679 100644
--- a/tests/providers.test.js
+++ b/tests/providers.test.js
@@ -120,11 +120,21 @@ test('Vonage HMAC-SHA256 matches canonical parameter vector', () => {
   }).valid, true);
 });
 
-test('Vonage rejects legacy MD5 unless explicitly allowed', () => {
+test('Vonage does not expose legacy MD5 algorithms', () => {
   const params = { timestamp: '1700000000', text: 'hello' };
-  const signature = createVonageSignature({ params, secret: 'secret', algorithm: 'md5hash' });
-  assert.equal(verifyVonageWebhook({ params, signature, secret: 'secret', algorithm: 'md5hash', maxAgeSeconds: false }).code, 'INSECURE_ALGORITHM');
-  assert.equal(verifyVonageWebhook({ params, signature, secret: 'secret', algorithm: 'md5hash', allowLegacyMd5: true, maxAgeSeconds: false }).valid, true);
+  for (const algorithm of ['md5', 'md5hash']) {
+    assert.throws(
+      () => createVonageSignature({ params, secret: 'secret', algorithm }),
+      /Unsupported Vonage algorithm/,
+    );
+    assert.equal(verifyVonageWebhook({
+      params,
+      signature: '00'.repeat(16),
+      secret: 'secret',
+      algorithm,
+      maxAgeSeconds: false,
+    }).code, 'CONFIGURATION_ERROR');
+  }
 });
 
 test('Plivo V3 matches a fixed HMAC-SHA256 vector and token rotation list', () => {